You need to place woopress-es_ES.po, woopress-es_ES.mo files into /wp-content/languages/themes/ folder.
Translation for child theme required only in case you made changes in files there. In case, you use the child theme, but did not add files with new strings, translation files for the child theme is not required.
Also, if you face problems with translation, you need to be sure that your translation files are synchronized. Button Sync (Loco Translate plugin http://prntscr.com/glemdq) allows you to synchronize your translation file with updated pot file. It means if we made any changes in template files that may affect translation or we added new string for the translation and you updated theme you need to synchronize your translation with updated files. Only after synchronization, you’ll be able to translate new strings or strings that were changed. Also, don’t forget to backup all the files before any update.
If you need any further assistance, provide temporary wp-admin and FTP access.